///-jiilrolieir/.eiK' IIikh-kU' 



l> 



y>-aiiiliiie iiuoi-Kie — 



jiitraiiiliiK' lliioridci 1 ; 2 : 4) DcS'' — 



beiizeiio fluoride — 41°. 2 (Sr/ 



( 330 ) 



111. p. I). ]). .-^i). t;r. at 84M-8 



r.7 205 1.2532 



2(r.5 205° 1,2583 



— 187° — 



1.023(5 (al 2074) 



Il is a well Iciiow ii f'acl llial llic lialoiicii iii llir lialouoi luMi'/cnes 

 is vei'\ iiitM'l l)iil llial oii fiirllicr siihsliliilion in llic hcii/ciic iiuclcMis ils 

 <lis})hu*CMii('iil iiiav lic iiiucli lacililalcd. In liow l'ai' lliis is llic casLMNilh 

 heiizeiie Hiioridc and ils dcrixalixcs lias received l»iil insid'licieiil iioliee up 

 lo the presenl. Wai.i.acii and IIkisi.kk A. 243. 242) slate llial sodiuni 

 acliiii;' al a üciillc lieal on an clliei-eal solnlion of l)en/enc llnoride 

 alistracis all llie lliiorine willi Ibi-nialioji ol' diplienvl. ^\(' repealed 

 Ihis experimcnl, luil noliccd l>nl lilllc lornialion ol'dijilienvl allliouuii 

 cuiisiderable ([uaidilics ol' resin were Ibrnied. Moi'coxer, llie sodinni 

 ^^■as bnl lilllc allacked. Anollicr proecs> lor sindvinu' tlic deeoniposilioii 

 of lialo.u'cn hcn/encs is tlial ot' Ll'iw lAni'.K'Z consislinu' in dissolxiiiü' llie 

 conipoujid in a larue excess of aleoliol and llieii addiii.U' sodium. If 

 wc call [Nd) llie nimiher of arani-alonis of sodium w liieli is prcscul 

 al a iLi'i\'eii moincnl in a kilo of' soh-cnl, '/ llie oriuinal lialoiieii 

 compound and ./ llie portion then coii\'erted we lia\'e accordiiiu' to 

 liini llie relation 



,l(Xa) 



K(<i — .r) 



in w liicli A' is a conslanl which he ^ixes the name of "useful eÜeer' 

 (Nulzeifeet). 



We i-epealed one of Lr»\\ kmikuz's e.\[»ei-iineiilal series \\ illi lienzenc 

 chloride and found the useful effect lo l>e 0. 2(51 whereas he had 

 fouml 0.254 aiid 0.2(58. 



On a|)phin,U' the |trocess to lienzeiie fluoride il was found llial 

 sodium N\ hen acliiiu' on its alcoholic solnlion does nol ahslracl a 

 Iraee of fluorine, so llial llie useful elfeel =:=(). This result is siir- 

 Drisiiii», hecaiise accordinu' lo the inxcstiuations of L('t\\ kmikk'Z the 

 useful effect is altoul etpiallv ^real for ihe other halo.uen henzeiies. 

 Il shows that lh<' lluoriiie in the nucleus is more lirmlv comhiued 

 than the other halo.u'eiis : some dala of Wallacu and Hkisi.kk a,«>ree 

 with this \ie\v, hir instance, that hv the action of sodium on an 

 ethereal solution of yyd»eiizene llnorohrtmiide for S davs a laruc amount 

 of sodium l»i-omide had separated hut luil a trace of Na V\. 



On the other hand we notice llie .ureal facililv with \\ liicli the 

 iluurine of the heiizene nitroflnorides reacts \\itli sodiuni metlnlate; 



